How do you remove the chuck on a 18volt Dewalt drill.

The black thing at the end is the "keyless chuck". Grasp it just behind the silvery tip of the chuck with one hand, and grasp the knurled ring just behind THAT area with the other hand. Twist the "front" hand counterclockwise while you twise the "rear" hand clockwise. That will loosen the chuck so you can change bits.

Open the chuck jaws and look down inside the chuck. You will see a screw head that is holding the chuck to the drill. Once you remove the screw, the chuck should pull off easily.

My solution when the other mentioned ideas didn't work was this: I removed the 7 Torx #20 screws ( a common screw driver will work as well) and removed the housing half to expose the shaft. The chuck shaft bearings and gear lifts out as one assembly. Directly behind the chuck there is a half inch section of shaft exposed. I mounted a vise grip on the shaft (won't hurt it) and clamped the affair in a bench vise. With a 5/16" allen wrench mounted in the chuck and using a mallet I spun the chuck off with a solid smack counter clockwise . Very simple and easy .

Look at eReplacementParts.com and the parts diagrams.

Remove the REVERSE-THREAD screw at the bottom of the chuck. Set the clutch collar to the highest setting, and set the gear to the slowest setting on the transmission. Remove the power source! Get the biggest allen wrench you can fit in the end of the chuck(the shortest leg) and tighten the chuck down around it, allowing the jaws to rest and tighten on the flats of the wrench. Lay the drill on its side(chuck toward you, handle to the left, and allen wrench to the left, horizontal to the deck). Then with a hammer(soft hammer if you care about the allen wrench) quickly and deliberately hit the allen wrench in an attempt to cause the allen wrench to spin counter clockwise. Let me know if this works for you!

there is a screw inside the chuck inline with it, I believe it has a reverse thread so turn it counter clockwise to remove

there is a flat head screw in the center of the keyless drill chuck counter clocwise to remove.

first shift the drill to the drill only position and the gear selector to the low position, remove the chuck retaining screw LH thread, find a bent handle allen wrench about the chuck capacity and lock in the jaws of the chuck, put the chuck on a block of wood at about a 30 degree angle to hit the long portion counter clockwise and strike it with a hammer, it might take a couple hits but it will come off. I misread the header last time.

Put the screw back in the chuck, tighten it up then back it out 1 turn. Take a punch, put it in the chuck and give it a quick hit with a hammer. That should do the trick.

I had the locking screw come loose in the center and bottom of the chuck it has a left hand thread and is a torx head . It had backed out and prevented the chuck from closing.